1. Field of the Invention
The present invention relates generally to a seat belt restraint system and, more specifically, to a seat belt restraint system which may be configured for use as a four point or three point seat belt restraint system.
2. Description of the Related Art
Automotive vehicle seats include a generally upright seat back mounted to a generally horizontal seat cushion for supporting a seated occupant. The seat back includes a top portion which often supports a headrest and a bottom portion which is often pivotally attached to the seat cushion for providing reclining adjustment of the seat back. The seat cushion extends between an inboard side (adjacent the center of the vehicle) and an outboard side (adjacent the outside of the vehicle). A seat belt restraint system is commonly secured to the seat or the vehicle structure surrounding the seat for restraining the seated occupant in the seat. The seat belt restraint system typically forms either a three point seat belt configuration or a four point seat belt configuration. The three point seat belt configuration is generally defined by including a lap belt webbing extending between the inboard and outboard side of the seat cushion and a shoulder belt webbing extending diagonally from the outboard, top portion of the seat back to the inboard, bottom portion of the seat back. The lap belt webbing and shoulder belt webbing are generally interconnected by a clasp, or latch plate, and the clasp is releasably latched to a buckle on the inboard side of the seat cushion. The four point seat belt configuration is generally defined by an inboard and outboard shoulder belt webbing extending from the top portion to the bottom portion of the seat back adjacent the respective inboard and outboard side of the seat to a corresponding inboard and outboard lap belt webbing extending from the respective inboard and outboard sides of the seat cushion. The clasp, or latch plate, interconnects with the buckle to interconnect the shoulder belt webbing with the lap belt webbing to complete the four point seat belt configuration.
It is also known to provide a seat belt restraint system for use with a vehicle seat which includes a three point seat belt configuration formed by a lap belt webbing and a shoulder belt webbing and further includes a four point seat belt configuration formed by a second shoulder belt webbing. U.S. Pat. No. 5,123,673 to Tame, issued Jun. 23, 1992, is an example of a seat belt restraint system including both a three point and four point seat belt configuration. However, these type of seat belt restraint systems typically require the use of multiple latch plates and buckles to interconnect each of the shoulder belt webbing and lap belt webbing in each of the three point and four point seat belt configurations.
It remains desirable to provide a seat belt restraint system which is comfortable, easy to use, and includes a single buckle and clasp for providing operation between either a three point seat belt restraint configuration or a four point seat belt restraint configuration.
Accordingly, the present invention is a seat belt restraint system for a vehicle seat having a seat back extending between a top and bottom portion and a seat cushion extending between an inboard and outboard side. The seat belt restraint system includes a first shoulder belt webbing extending from the top portion to the bottom portion of the seat back adjacent the inboard side of the seat cushion and a second shoulder belt webbing extending from the top portion to the bottom portion of the seat back adjacent the outboard side of the seat cushion. The seat belt restraint system further includes a first lap belt webbing extending from the inboard side of the seat cushion to the first shoulder belt webbing adjacent the bottom portion of the seat back and a second lap belt webbing extending from the outboard side of the seat cushion to the second shoulder belt webbing adjacent the bottom portion of the seat back. The seat belt restraint system includes a clasp interconnecting one of the first and second shoulder belt webbing to the respective one of the first and second lap belt webbing and a buckle interconnecting the other of the first and second shoulder belt webbing to the respective one of the first and second lap belt webbing for lockably receiving the clasp. The seat belt restraint system also includes a buckle anchor fixedly secured adjacent one of the inboard and outboard sides of the seat cushion for lockably receiving the buckle. Finally, the seat belt restraint system includes a first connect mechanism secured to the buckle for releasably locking the clasp to the buckle to define a four point seat belt restraint configuration with the buckle and clasp positioned generally midway between the inboard and outboard side of he seat cushion and a second connect mechanism secured to the buckle for releasably locking the buckle to the buckle anchor to define a three point seat belt restraint configuration with the clasp releasably locked to the buckle and the buckle releasably locked to the buckle anchor adjacent one of the inboard and outboard sides of the seat cushion.
The seat belt restraint system is easy to use because it includes a single buckle and clasp for connection between either the three point seat belt restraint configuration or the four point seat belt restraint configuration. Further, the buckle includes both the first connect mechanism for releasably locking the clasp to the buckle in the four point seat belt restraint configuration and the second connect mechanism for automatically releasably locking the buckle to the buckle anchor in the three point seat belt restraint configuration when the first outboard shoulder belt webbing is extended diagonally across the seat back and the clasp is releasably locked to the buckle by the first connect mechanism. Still further, the seat belt restraint system is more comfortable by including a pair of D-rings in the seat back which receive and guide the first and second shoulder belt webbing between the three point seat belt restraint configuration and the four point seat belt restraint configuration.
Other features and advantages of the present invention will be readily appreciated as the same becomes better understood after reading the subsequent description when considered in connection with the accompanying drawings.